On Monday I finished what I started with this blog back in September of 2008.

I ran a marathon.

It was the first and only such endeavor of my life and momentarily I will impart, in glorious detail, the day's soaring highs and near-death lows.

But first, a word to my sponsors, meaning those of you who forked over the cash to help people with AIDS and HIV, and so I could get the training I needed to do this thing.

Thank you.

If you're a faithful follower of Run On, you know that my marathon journey began with a diminutive brochure packed with big promises.

Run a marathon even if you've never run before!, it said, and raise money for people with AIDS and HIV while you're at it.

I did, and I did.

In fact I outdid. I ran longer and faster than I ever have in my life and I raised plenty more than I was asked to.

Plus I blogged about it, providing a fleeting weekly diversion for lots of people who may have never run an inch in their lives (not unlike myself, before September) but who read blogs because you can do that without moving.

Which brings me back to the sponsor part. Because if you didn't sponsor me, guess what? You can still help people with AIDS and HIV. Lucky, lucky you.

AIDS Project Los Angeles, the beneficiary of my marathon run, is a key source of care and services for thousands of Los Angeles residents living with AIDS and HIV, many of whom subsist on $10,000 a year. Imagine what your life would be like living on $833.33 a month. Now imagine what it would be like to live on that and have AIDS.

And now our governor, in his infinite wisdom, is planning to eliminate funding for medication for 35,000 indigent Californians with AIDS and HIV. Yes, we're in a budget crisis, but really? Really?

APLA does great work. They're helping folks who are being hit hardest by our current economic meltdown. They might even send a contingent up to Sacramento to talk some sense into the governor. If they could afford it. But their funding is shrinking like everyone else's. That's where you come in.

Think of the diversion from real-life concerns this blog has provided you, the vicarious armchair thrill lo these many months. How much is that worth to you? A hundred bucks? Fifty?

Now we can get on to the marathon part, titled "My Marathon in Neurochemistry: The Brain Candy that Fueled Me, Nearly Killed Me and Then Sent Me Over the Moon, A Completely Unscientific Account of What I Experienced and Why Based on Cursory Web Research (mostly from the Runner's World website), Inference and Intuition."

Part I: Fueled Me

It's 6 a.m., Memorial Day 2009, when all right-thinking people are still in bed, dreaming of barbecue. We are standing at the corner of Fourth and Figueroa in downtown LA trying to grasp what it is we are about to attempt.

"We" is my group of eight, part of a larger group of runners trained by the AIDS Marathon fundraising outfit.

We've been together for months, training independently during the week and then together every Saturday morning. Our group is one of the slowest. We're not jocks, hell we're not even in particularly good shape. But for one reason or another we all signed up for this challenge and stuck it out.

We're all in the midst of some sort of drastic life change. In the months since we began there have been two marriages, a divorce, a home sale, a relationship breakup, a moving in with significant other, a set of adult braces, the purchase of a Mini (red) and way too many birthdays.

Now we're just trying to figure out how to make it through the next six, seven or however many hours it might take to run around the city and wind up right back where we are right now.

We make our way to the starting line, which is about a block long. The elite women start first and then there's a 17-minute lull before the rest of us are let loose. Cell phones come out for a last quick bout of texting.

Andrea takes a hit off my inhaler. Amy uses my Body Glide.

I show off the red marks in my right knee where I got a cortisone shot to ward off the IT pain that has wreaked havoc on my recent long runs and that I fear will wreck me today.

Rachel shows me how to position the strap I bought to wrap around my right knee in case the shot fails to do the job.

We stand. We breathe. We wait. We feel the adrenaline, which, according to Runner's World, "comes with getting excited for a race, [and] which also has the power to boost confidence and kill pain." Good.

The horn sounds and we're swept up in a giant mass of forward motion. We're somewhere in the middle of this massive crowd, but everyone is calm.

This does not at all resemble my typical crowd experiences, like the time I was on the green at Soldier Field for a Bruce Springsteen concert and was nearly suffocated in the press toward the stage.

Though we are all moving forward, we are each our own show. No need to get to the front for that.

The street is wide and after a short while there's plenty of space to move. The challenge is to go slow and stay that way for a good long while.

According to Coach Scott, who's been right about everything else, if you start off fast you burn through your reserves and risk flaming out before the finish. Best to keep it slow and steady, then if things go well build up speed later.

I am especially receptive to that message because I'm worried about my knee. If it's going to crap out I want to prolong the moment of collapse as long as I can.

Part of our group immediately pushes ahead. I see them in the distance, like a bottle bobbing away on the tide. We stay slow, like uncertain swimmers who don't really know the strokes.

We're running slightly downhill, which feeds the urge to speed up. But slow we go, south down Fig, then a jog around USC, then onto Exposition Boulevard.

The course looks like the profile of a Scottish Terrier, where the start and finish are the tail. Mile one is the butt and mile three the hind leg.

I think about the map from time to time throughout the run. Am I wagging this dog or is it wagging me?

The weather is gorgeous - a heavy marine layer that hangs on for most of the day. Rachel points out that for all our carping about the marathon date being pushed back to the end of May and how it was going to be miserably hot, we wound up getting a day that was better than either the original race date of Sunday, March 1 (unseasonably hot) or the President's Day alternative (windy, rainy and miserable).

I'm feeling good and strong and my right knee is quiet. Is it the cortisone, or is it anandamide, from the Sanskrit word for 'bliss,' and which, according to Runner's World, "is very similar to THC, and it produces pleasant feelings of relaxation and pain cessation similar to those often described by runners and pot smokers."

Whatever the cause, I'm sharp, focused and contemplating my environs. What would Martin think about all this running? He liked street theater. Would he find a way to work the marathon into his vision? It seems to fit. I can see him here, smiling, waving, rejoicing in this fleeting coming together in the places where brown and black people live.

By now we're well over two hours into the run and the top runners have crossed the finish line. And look who won.

Among the men all the winners are black. Among the women several are as well. They are Kenyan, Ethiopian. African.

So why does the image on the official LA marathon poster, t-shirt and pin feature a pair of white legs? Will LA, the land of illusion, ever embrace the value of reality?

Back on Crenshaw we head north across the 10 Freeway. Almost to mile 12, we swing onto Venice and head west. The vague gloominess of Mid City is brightened by the sight of Coach Scott and a few other AIDS Marathon trainers who run up and check on us, offering us water, sunscreen and moral support.

My knee is feeling fine, but I pop an ibuprofren just in case. Just past mile 13, I get a text message from the marathon pace keepers. They offered this nifty service where you could pre-register your runner number and cell number. Every time you cross a censor they send you your pace. This was second notification. The first, around mile 6, put me at a 15 minute, 5-second per mile pace. My predicted finish time was 6:35:27.

Now I'd been running just over three hours and my pace was 14 minutes 14 seconds. My predicted finish time was 6:13:10.

I'd started off slow and now I was slowly increasing my speed, just like Coach Scott advised. I'd trained at a pace of 14 minutes, 30 seconds per mile. Coach Scott said that if all went well (no knee tweaks or flame-outs) we could expect to run the marathon at a pace of between 30 seconds and a minute per mile faster than our training pace. Sweet!

Mile 14, Venice and Fairfax, the chin of the dog, and there are my husband Mark and the kids, Genevieve and Lucas. I stop and kiss them all, sharing my runner's fug.

"Hi Mommy! You're more than half way!" Genevieve hands me a new bag of fuel (fuel being the overpriced gooey chewy stuff that comes in glossy packets at running stores) and off I go. I pack my pouch and hand out the rest to the group.

By now the runners in the group begin to fall away. Though we've run as a group throughout the training, today we each run for ourselves. We agreed in advance that we're all going to push ourselves, which will probably mean something different for each person.

We're down to four and moving along, just far enough that the first wave of endorphin giddiness hits. Past the halfway point and feeling good. Yes indeed, all is well.

At water stops we revel in taking a few slurps and flinging the still water-laden cups willy nilly into the gutter. The joy of littering. A moment of marathoner exceptionalism.

Around Mile 15 I get a text message from Genevieve, who is 9 and very tech-savvy. "Hi mommy u rock keep going and eating ur chewy things ur the best love Genevieve." I giggle madly.

At Mile 17 we come upon a massive pair of hairy gonads. A Manny Ramirez sympathizer? No, just a guy with a sense of humor trying to build awareness about testicular cancer.
(This image is from a different event, but the costume is the same.)

Mile 18, Carthay Square, and there's the family again, for one last cheer before they head to the finish line to wait. "Did you see the man who looked like a giant peanut?" Lucas, who is nearly 7, asks. "Um, yeah," I say, glad to be off and running before the inevitable follow-up questions.

I get my third pace text. I've been running for 4 hours, 22 minutes and 54 seconds. My pace is 14 minutes, six seconds per mile. My predicted finish time is 6:09:41. I'm continuing to pick up steam.

Mile 19. Sixth Street, Hancock Park. The houses are large and lovely and set back. The road is curvy and hilly. A woman stands with a tray full of beer shots. "You can drink and run at the same time," she shouts, joyously. "Come and get it!"

Beer is the last thing I want right now. I'm starting to feel the urgent need that so horrified my friend and co-marathon champion Sara Stein when she heard about it early on in our training. A woman shakes a sign at me that reads "Sweat is Sexy!"

All I want is a bathroom. I pick up the pace to Mile 20. The Porta Potties are wide open. Disaster averted.

We're down to two runners, Rachel and me. And thus ends the happy portion of the run.

Part II: Nearly Killed Me

We continue on. The final Six-Point-Two. I try to think of that length in its smallness, in its manageableness, but somehow, even as I move forward, the finish line seems to move further away.

The most I've ever run before this is 23 miles. Once. A couple of months ago. Every step I take from here on out is uncharted territory. Already it feels hard, harder than I'd expected, especially given that my knee is fine.

I'm hit with a gloomy realization - I've forgotten to take my fuel, and I know exactly when.

It was after that bathroom emergency at mile 20. I felt relieved, and not at all hungry. I had more fuel in my pouch and I was going to wait a while to make sure my digestive tract was settled before fueling up. But I completely forgot, which was a very bad thing, because it was at mile 20, when my natural reserves were entirely depleted, that I needed it most.

Where did my memory go? It's not like I had a lot else to think about. Blame it on the endocannabinoids, "substances released with exercise that produce an effect similar to a marijuana high," according to Runner's World. And maybe marijuana's forgetfulness, too?

Now it was too late. Once the reservoirs are empty, the body's entire process of generating energy is knocked out of whack. You can't just dump the goo into the empty hole.

"When you run for long periods, you drain your muscles of glycogen, which is the form that carbohydrates take when stored in muscle tissue. When glycogen stores run low, fatty acids (released from fat cells) become a primary energy source.

"Now it gets tricky. Fatty acids require a special carrier to take them through the bloodstream. The problem is that there's another substance that rides this same carrier. That other substance is called tryptophan, an amino acid that the brain converts to serotonin. What happens is that during endurance exercise, increasing numbers of fatty acids bump tryptophan off its carrier. The free-floating tryptophan enters the brain (it has a biochemical "preference" to do this), where it converts to serotonin. The result? Serotonin levels increase, and you feel tired."

The perfect storm of fatigue, under-nourishment and continued energy-demanding motion are filling me with a venom of weariness and defeat.

I am thirsty. My mouth is sandpaper. I'm scorched, parched, burnt from the inside out. Where can I find something to drink?

Cups are scattered across the road, then the most blessed sight: a table with water. A man in an orange turban fills my bottle.

"Thank you," I say.

"Thank you for running," he says, in a voice so kind I nearly cry.

The road is wide and dry and dirty and overly bright. Mile 24, the back of the dog. Still on wretched Olympic. Everyone seems to be walking or limping.

What happened to the marathon, I wonder. Is it over?

And then it hits me. Of course not. This is it. This is what makes it a marathon.

For all these months I never really got it. Why do people think running a marathon is so hard? Unless you're an elite runner and going for a world record.

But if you're running at a comfortable pace, what's the big deal? You just need the discipline to build your mileage, and if you do everything as you should, all will be well.

True, if you get injured, that's a barrier and you try to take care of it as best you can. But barring injury and keeping up the training, what's the big deal?

Now I know. All the work that I'd done, all the care that I'd taken had gotten me this far. Right here. Mile 24. And this was as far as it was taking me.

My strength was sapped, my spirit was weak. There was nothing I could put into my body now that was going to get me to mile 25, let alone across the finish line.

"I started out strong, but at mile 20 I hit the wall," a man says into his cell phone. "No, no, not a real wall. I'm fine, I'm fine."

The dreaded wall. Is this my wall? Am I dying? Do I need to stop? Will I regret it if I stop? Will I regret it if I don't?

My stomach is pushing stuff up into my throat. My head refuses to stay up straight. Am I going to pass out?

"How's it going?" chirps a man in a bright yellow AIDS Marathon shirt who has popped up next to me.

"Okay," I say.

Or did I say it? I have to concentrate to get my mouth to open. Was I just thinking about saying it or did the words come out?

"Are you feeling light-headed?"

"No," I lie. What if I say yes? Will he make me stop?

"Great!" he says, grinning. Why does he have so much energy? Where did he get it?

"Okay," he says. "First let's get you back up to the center of the road."

I hadn't noticed that Rachel and I had veered off to the side and were running with our feet at a 45-degree angle. We follow him to the middle.

"Now, here's what you need to do. I want you to take it very easy until you get to mile 25. Then you can pick up the pace and enjoy that home stretch."

Okay, good idea. Take it easy. Can I do that? Is that okay? Is it okay to take it easy? Isn't that giving up? No, no. Good idea. I will do that, yes I will.

"Remember, you're helping people live longer," the happy man says before he jogs off.

I slow to a walk. Rachel keeps going.

"Keep going," I say, waving to her back. And for the first time in the race I am alone. I keep moving, but at a walk.

I concentrate on not throwing up or falling down.

I try to run but I can't. My body won't let me.

I call Mark.

"Tell me something good."

"Look up. See downtown? See the building where I work? See how close you are? That's where you're going. You're almost there. It's so close. Do you see it?"

That white wedding cake of a tower. I hadn't even noticed it but it's right there. Just seeing that building there is comforting. The world is fine. The buildings are standing. Everything is okay.

"Yes."

"See what I mean?"

"I do, I do. Tell me something else."

"Genevieve and Lucas are so excited and so happy and so proud. I'm so proud of you, honey. You've worked so hard."

I'm choked up and teary.

"Can I do this?"

"Of course you can."

"Okay," I croak, and hang up.

Mile 25. Just a mile and a smidge to go.

I start running. I want to puke.

My head feels like it has detached itself from my body and floated away. Good. Then I won't puke. I see a green balloon in the distance. Is that my head? If I cross the finish line without my head will it still count?

Will my body still move forward without my head, the way nails and hair continue to grow after a person dies? Or will I just fall down? I might.

No. Not now. Too close for that. Don't think about miles. Think about blocks. Miles are long. Blocks are short. Just a few more blocks. I envision my childhood home, a red brick row house on Chicago's Near South side, neatly laid out with dozens of other red brick row houses, all exactly the same, filling a city block. I see myself circling that block, once, twice, how many times around that block to make it to the finish?

Oh, finally off that hideous Olympic Boulevard. Why do they call it Olympic when it's so ugly and bright and stark and horrible? It's an Olympic feat just to run on Olympic.

The tail of the dog and here are the crowds. They're cheering. They're excited. They're pressing in against the barriers. This is where it ends and everyone wants to see it.

Will it be a happy ending? Yes it will.

Somehow I'm running and smiling and waving, and there are Mark and the kids smiling and waving back.

I'm at the finish. I remember to hold my arms up over my head like everybody told me to.

Final time: 6:03:43. Pace: 13:53.

I did it. I'm done.

Part III: Sent Me Over the Moon

I float through the fenced off runner's zone. A medal is draped around my neck. I'm handed a marathon bag, some salt-and-pepper cashews and a shiny blanket thing that I'm supposed to wear like a cape, but I'm way too hot and dizzy and nauseous for any of it.

"How are you feeling?" a very handsome paramedic asks me.

"I'm fine," I say. "How are you feeling?" He laughs.

"Fine," he says.

It's odd and trippy. I trained for eight months, and in the past few minutes I've gone from marathoner wanna-be to an actual, real-life marathoner.

I see Rachel and together we work our way to the Bonaventure, where we're told there's a garden deck with food and music and massages just for the AIDS Marathon crowd.

We walk and walk and wander and I have no idea where we are. There are people everywhere eating and talking and going about their lives.

We go up some stairs and through some doors and we're on an escalator and there are Mark and the kids, waiting for me, and all the sick and dizzy falls away.

"Mommy!"

We walk around some more in the maze that is the Bonaventure, which I don't mind at all. It's thrilling just to meander without having to worry about throwing up or falling down.

Eventually we find the private garden deck area and I recline on a lovely cushioned sofa thing and Genevieve brings me an apple and a granola bar and Lucas massages my back with ice.

There is no place in the world I would rather be than right here, with him. He is the most important thing, not the marathon or bills to pay or stuff to write or irritations or obligations or any of the other always-present baggage of life.

After 18 years, two kids, a million responsibilities and woes, I'm left with one plain truth, a truth that maybe in these recent months (years?) with all the other stuff going on that always seems to be going on I might have kind of forgotten: that I love him strongly and deeply and with my entire being.

It is the best, most wonderful, absolutely unexpected surprise of this entire marathon experience.

(Right about now you're rolling your eyes. Oh please, you're saying. This is all a bit much, isn't it? Well, yes, it is. But as unbelievably sentimental and silly and overwrought as it sounds, that's what happens when you're on drugs, even the running-induced kind.)

It is beyond a runner's high.

It is the pretty side of the ugly, cannibalizing neurochemical meltdown that nearly did me in.

The serotonin sweet spot. Nature's ecstasy. Hubby love.

From Science Daily:"Ecstasy, which is known chemically as methylenedioxymethamphetamine, or MDMA...causes neurons, or nerve cells, to release serotonin, a neurotransmitter that controls mood, pain perception, sleep, appetite and emotions."

From Scientific American: "What are the effects of the drug ecstasy? Feelings of euphoria, enhanced mental and emotional clarity, sensations of lightness and floating."

And I only needed to run 26.2 miles and nearly die to get there.

Since I'm sharing the love, here's an embrace for my fellow runners, the German Silvas (get the lowdown on the name here and here). We started out with 20-something and finished with a core of eight, a strong group, a mighty group.

Running is ultimately a solitary sport, but it was my team that got me (almost) through. Thank you to: Dwayne Johnson-Cochran (7:13:30) for planting the cortisone seed; Eun Kyung Lee (6:42:29) for urging everyone on; Sandy Lin (6:15:20) for the sunglasses that became my good luck charm; Andrea Cavanaugh (7:11:16) for cracking me up, back-up blogging and editing this extremely long piece; Amy Finn Bernier (6:42:28) for sticking with it; Rachel Tronzano-Ryan (6:02:45) for getting me to almost the very end on marathon day, and Gaby Vergara (6:11:14) for inspiring us all.